I might, indeed, have learned, even from the poets, that Love is something more stern and splendid than mere kindness: that even the love between the sexes is, as in Dante, "a lord of terrible aspect." There is kindness in Love: but Love and kindness are not coterminous, and when kindness (in the sense given above) is separated from the other elements of Love, it involves a certain fundamental indifference to its object, and even something like contempt of it. Kindness consents very readily to the removal of its object--we have all met people whose kindness to animals is constantly leading them to kill animals lest they should suffer. Kindness, merely as such, cares not whether its object become good or bad, provided only that it escapes suffering.
C. S. Lewis, The Problem of Pain, Collier (New York: 1962) pp. 40-41. The meaning of kindness as used here is glossed as "the desire to see others than the self happy; not happy in this way or in that, but just happy" (p. 40).